Electric-circuit-testing device



(No Model.) M. ROBINSON.

ELEGTBIU CIRCUIT TESTING DEVICE. No. 400,951. Patented Apr, 9, 1-889.

WITNESSES: INVENTOR,

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UNITED STATES PATENT OFFICE.

MINER ROBINSON, OF NEIVTON, MASSACHUSETTS.

ELECTRIC-CIRCUlT-TESTING DEVICE.

SPECIFICATION forming part of Letters Patent 0. 400,951, dated April 9,1889.

Application filed June 11, 1888. Serial No. 276,709. (No model.) I

To all whom, it may concern-.-

Be it known that I, MINER ROBINSON, a citizen of the United States,residing at Newton, in the county of Middlesex and State ofMassachusetts, have invented a certain new and useful Improvement inElectric-Oircuit Testing and Detecting Devices; and I do hereby declarethat the following is a full, clear, and exact description of myinvention, such as will enable others skilled in the art to which itappertains to make and use the same.

My invention relates to electric gas-lighting systems. It has been foundin using these systems that considerable difficulty arises from faultycircuits caused by a sticking of the electrodes at the burners from aground, a short-circuit caused by bad insulation, or a leak, and thesefaults havegiven rise to great inconvenience and trouble for the want ofa quick and convenient device for detectingin which circuit the faultlies and for cutting out that circuit from the system, so that thebattery will not be needlessly used up. I have invented such a device;and-it consists, generally, of a base carrying a center post to whichone side of a grounded battery is connected. This post is'also adaptedto be connected with all of a series of contacts arranged around it, thecontacts constituting the terminals of the wires from the differentburners in the system. The normal condition of the circuits is closedthrough the contacts and the center post and open at the burners. If, byaccident or otherwise, the electrodes at a burner stick together, andthus complete that circuit, an alarm is rung notifying the attendant ofthe fact, and he may immediately break all the circuits at the board bysevering connection between the center post and the contacts. This stopsconsumption of battery.

, Then by passing a brush or electrode having a connection with thecenter post around the board, touching each of the contacts insuccession, the faulty circuit may be detected by the formation of aspark when the brush passes over its contact-terminal; or, if there isnot a complete circuit in the system, but simply a leak, the same may befound by noticing the movements of a galvanomet-er placed in thebrush-circuit when the brush is passed over the contacts.

I have illustrated my invention in the accompanying drawings, in which'Figure 1 represents a plan of the testingboard with a diagram of thecircuits. Fig. 2 represents a section of the testing-board, and Fig. 3is a detail.

Referring to the drawings by letter, A represents the base or supportupon which are mounted the devices constituting my invention,

B is the battery, grounded at G A, a sparking-coil, which, whenenergized, closes alocal bell-circuit, M.

O is a system of gas-piping, which constitutes a conductor for thecurrent and grounds the same to complete the battery-circuit.

In the center of the support A, I fix a post, a, which is connected withbattery through the sparking-coil. This post projects above the surfaceof the base, and is adapted to receive a metallic knob or nut, (l, whichhas a cen tral perforation for the purpose. The knob has a neck, Z), anda cross-head, b the latter of which is adapted to pass through an oblongslot in a plate, b and be held beneath the plate when the knob is givena partial turn. A spring, I), surrounds the post and resists thedownward movement of the knob. The terminals c of the wires from all thegas-burners in the system are located in a circle around the outer edgeof the board or base, and these are all adapted to be connected with theknob and center post by means of two metallic strips, a and 0 for eachcontact. The strips 0 are rigidly secured to the base by screws and theinner ends bent upward to about equal distances, so as to make contactwith the knob simultaneously. The strips or switches c are pivoted, incontact, to the strips 0', and their outer ends are provided with knobsby which to swing the strips into and out of contact with the severalcircuit-terminals. Stop-pins c are provided to limit the movement of theswitches.

I have connected with the center post, a, a flexible conducting-cord, I,having at its free end a contact brush or trailer, I, for a purpose tobe hereinafter explained.

The normal position of the knob b is down in contact with the strips 0,and strips 0 are in contact with the terminals. The circuits are thenfrom grounded battery to post a, to knob, to strips 0 and 0 to terminals1;, to line and burn ers, and through the piping to ground. The circuithowever is, as usual, open at the burners.

Now, if in. igniting the one of the vibrators or other form of sparkingdevice should stick and hold the circuit closed, this would energizecoil A sutiicicntly to hold down its armature and keep the local bellcircuit closed. The ringing of the bell indicates to attendant thatthere is trouble, and to prevent waste of battery he goes about todiscover which circuit is closed. lle first breaks all the circuits(from each other and from the battery) by lifting the knob from thestrips 0, and, then taking the brush or trailer I in hand, he passes itaround the board, making contact With each of the strips (1 and c insuccession. "When contact is made or broken with the strip in the faultycircuit, a spark is produced. He simply opens that switch, returns theknob, and the apparatus is in order again except for the one faultycircuit, which may be repaired at leisure. The location of the faultycircuit is indicated by the numbers on the switches.

It a test is desired for a leak, the brush is used in the same manner,and a galvanometer, I], in the brush-circuit will show a deflection ifthere is any leakage.

Obviously this device is adapted to annunciator and other systems havinga similar arrangement of circuits, and I therefore do not confine myselfto gas-lighting systems alone.

Having now described my invention, what I claim is 1. A series ofnormally-open grounded circuits terminating at a testing-board,gasignitin g apparatus in said circuits, a series of manually-operatedswitches on said board for connecting the circuits with a generator, asparking-coil between the circuits and the generator, and a localbell-cireuit adapted to be closed by the sparking-coil, as set forth.

2. The base or board A, having central post, a, the knob (Z, strips 0and c and contaetsc, for the purpose set forth.

In Witness whereof I have hereunto fixed my seal and signed my name inthe presence of two subscribing witnesses.

MINER ROBINSON.

\Vitnesses:

(-IIAS. ROBINSON, 'Fmxnexs K. Hwnrrrsnn.

